Battery cell arrangement with improved housing

Abstract

The present invention relates to a battery cell arrangement, comprising: at least one battery cell (2), a cell holder element (3) at least partially enclosing the battery cell (2), a multi-part housing (4) designed to accommodate the battery cell (2), wherein the housing (4) comprises at least a first housing part (6), in particular a side part, and a second housing part, in particular an interface housing part or a cover, wherein the first housing part (6) has a first form-locking element (60), the second housing part (5) has a second form-locking element (51), and the cell holder element (3) has a third form-locking element (31), which are designed for form-locking connection to one another, wherein at least one of the form-locking elements, in particular the second form-locking element, is designed as a protruding form-locking element, wherein the protruding form-locking element engages in the other two form-locking elements.

Description

State of the art

[0001] The present invention relates to a battery cell assembly having an improved housing, particularly with regard to shock or impact.

[0002] Battery cell housings are known in various designs from the prior art. The housing of a battery cell assembly is usually made up of several parts, including a cover and, if appropriate, several side parts or a base plate. A guide arrangement, such as rails or the like, is often provided on the housing to allow the battery cell assembly to be inserted into an electrical consumer, such as a power tool or the like. The individual parts of the housing of the battery cell assembly are usually connected to one another by means of screws. In the event of an overload, such as if the battery cell assembly falls from a great height, the housing or parts of the housing may become detached from the rest of the battery cell assembly, depending on the height of the fall and the position at which it hits a surface.It would therefore be desirable to have a battery cell arrangement with improved shock resistance and robustness. Disclosure of the invention

[0003] The battery cell arrangement according to the invention with the features of claim 1 has the advantage that a housing can be attached to the battery cell arrangement more securely. This makes it possible to increase the robustness of the battery cell arrangement and, in particular in the event of a fall from a great height onto a surface, to avoid damage to or detachment of housing parts of the housing of the battery cell arrangement. This is achieved according to the invention in that the battery cell arrangement comprises at least one battery cell, in particular a round cell, a cell holder element, in particular a heat sink element, and a multi-part housing. The battery cell is at least partially, preferably around its entire circumference, enclosed by the cell holder element. The multi-part housing is designed to accommodate the battery cell and the cell holder element.The multi-part housing comprises at least a first housing part, in particular a first side part, and a second housing part, in particular an interface housing part or a cover. The second housing part preferably comprises guide regions, in particular guide rails and guide grooves, which are designed for connection to an electrical device. The electrical device is in particular an electrical machine, e.g. in an electric bicycle, an electric drive, or an electric drive in hand tools. The guide regions are preferably arranged on the cover, but can also be arranged on other housing parts, e.g. the first housing part. The first housing part comprises a first form-locking element, the second housing part comprises a second form-locking element, and the cell holder part comprises a third form-locking element. The form-locking elements are designed for a form-locking connection with one another. That is,that at least one of the form-locking elements can be positively connected to the other two form-locking elements. At least one of the form-locking elements, in particular the second form-locking element on the second housing part, is designed as a protruding form-locking element, wherein the protruding form-locking element engages in the other two form-locking elements. The other two form-locking elements are preferably recesses or openings. The other two form-locking elements are preferably provided as openings that are complementary to one another. The protruding form-locking element thus runs through the two openings on the second housing part and on the cell holder element. This allows additional fixation of the first housing part, in particular on the cell holder element, to be achieved.

[0004] The inventive concept makes it possible, in particular, for the battery cell assembly to eliminate the need for additional reinforcements in guide areas and / or guide grooves, which are located particularly on the cover of the battery cell assembly. Thus, the interfaces to electrical devices on the battery cell assembly, some of which have been present for years, can remain unchanged, while the battery cell assembly still has a more robust structure.

[0005] The subclaims show preferred developments of the invention.

[0006] Preferably, at least one of the form-locking elements has a reinforcing element, in particular an insert made of metal or sheet metal. This can provide additional security and stiffening of the form-locking elements.

[0007] Further preferably, the cell holder element has a protruding flange with a first opening as the third form-locking element, and the second housing part has a second opening as the second form-locking element. The first housing part has, as the first form-locking element, a protruding element complementary to the first opening and the second opening, which is received in the first and second openings. This allows for a particularly simple and compact design.

[0008] Preferably, the first opening of the cell holder element is a through-opening, in particular a polygonal one, in particular a square one. Further preferably, the second opening in the second housing part is also a through-opening, in particular a polygonal one, preferably a square one.

[0009] Particularly preferably, the cross-sections of the first and second openings are identical. This ensures that the protruding element, which is accommodated in the two openings, distributes forces evenly between the cell holder element and the cover when subjected to a load. This prevents load peaks, for example, if the battery cell assembly falls.

[0010] The protruding element of the first housing part preferably comprises a rib, in particular with a polygonal, in particular quadrangular, cross-section. It should be noted that the protruding element can also comprise a plurality of ribs having identical and / or different cross-sections. Accordingly, a plurality of first and second openings are then formed in the second housing part or in the cell holder element.

[0011] Further preferably, the second housing part has a protruding edge in which the second opening is formed. Preferably, an undercut is additionally formed on the protruding edge, which is arranged between the cell holder element and the rib of the first housing part. The undercut significantly increases the load-bearing capacity of the connection between the housing parts.

[0012] For an even more secure and robust connection, a snap-in connection is preferably formed between a free end of the first protruding form-fitting element of the first housing part and the second housing part and / or the cell holder element. The snap-in connection is, for example, a locking lug with a beveled edge, which snaps into a final position after the first housing part has been fully assembled. To release the connection between the first housing part and the second housing part as well as the cell holder element, the snap-in connection must first be released in order to separate the parts from one another.

[0013] Further preferably, a screw connection arrangement is provided between the first housing part and the second housing part. The screw connection arrangement comprises a plurality of screw connections, which can preferably be screwed into screw-in openings in the cell holder element. It is also possible for a screw of the screw connection to be additionally guided through an opening in the second housing part. This creates an additional connection between components, which further enhances the robustness of the battery cell arrangement.

[0014] Further preferably, the connection between the cell holder element, the second housing part, and the first housing part is provided without adhesive. This results in a cost advantage, since the connection arrangement according to the invention eliminates the need for additional auxiliary materials such as adhesive or the like. The inventive concept can also achieve an improvement in the quality of the battery cell arrangement, thereby increasing, in particular, user satisfaction with the battery cell arrangement by extending its service life.

[0015] Preferably, the housing of the battery cell arrangement also comprises a third housing part in addition to the first and second housing parts, wherein the connection between the third housing part, the cell holder element, and the second housing part is implemented in the same way as for the first housing part. The first and third housing parts are preferably side parts of the battery cell arrangement. It should also be noted that the housing can also comprise a base part, wherein a connection between the base part, the cell holder element, and the first and / or second housing part is implemented in the same way as described above.

[0016] Preferably, the component(s), in particular the side panels, the heat sink, and / or the guide rail, are each made of different plastic materials. As a result, these different components have different mechanical properties. This allows for individual adaptation of the battery cell arrangement to different external conditions. For example, the guide rails can be made of a more stable plastic than the side panels.

[0017] Further preferably, the distance between the second form-locking element and a guide region of the battery cell arrangement on the second housing part is at most five times, in particular three times, the height of the second form-locking element. Preferably, the distance between the second form-locking element and the guide region is at most 30 mm, in particular at most 20 mm, and further in particular at most 10 mm. Short description of the drawings

[0018] Preferred embodiments of the invention are described in detail below with reference to the accompanying drawings. In the drawing: Fig. 1 is a schematic exploded view of a battery cell arrangement according to a first embodiment of the invention, Fig. 2 a perspective view of a battery cell with heat sink element of Fig. 1, Fig. 3 a schematic, perspective interior view of a side part of the battery cell arrangement of Fig. 1, Fig. 4 a schematic, perspective view of a cover of the battery cell arrangement of Fig. 1, Fig. 5 a schematic sectional view of the battery cell arrangement of Fig. 1, Fig. 6 an enlarged partial sectional view of the battery cell arrangement of Fig. 1 in the connection area between the heat sink and housing components and Fig. 7 a partial sectional view corresponding Fig. 6 under tensile load, and Fig. 8 is a schematic partial sectional view of a connecting region of a battery cell arrangement according to a second embodiment of the invention. Preferred embodiments of the invention.

[0019] The following is based on the Fig. 1 to 7 a battery cell arrangement 1 according to a first preferred embodiment of the invention is described in detail.

[0020] As from Fig. 1, the battery cell arrangement 1 comprises a plurality of battery cells 2, which are surrounded by a cell holder element in the form of a heat sink element 3. The battery cells 2 are round cells in this exemplary embodiment. The heat sink element 3 encloses the round cells at a circumference and between the individual round cells, which can be seen in detail from Fig. 2 is evident.

[0021] The battery cell assembly 1 further comprises a multi-part housing 4. The housing of this exemplary embodiment comprises a first side part 6 (first housing part), a second side part 7 (third housing part), and a cover 5 (second housing part). The housing 4 of the battery cell assembly thus does not enclose all parts of the heat sink element 3, so that the heat sink element 3 is at least partially exposed and visible. This allows for improved thermal management.

[0022] On the heat sink element 3, as shown in Fig. 1, a battery management system 20 for controlling and / or regulating the battery cells is arranged. The battery management system 20 is completely covered and protected by the cover 5.

[0023] Furthermore, guide areas 50 in the form of rails and adjacent grooves are arranged on the cover 5. This allows the battery cell assembly to be inserted into correspondingly designed counter-rails on an electrical consumer, e.g., a power tool. Furthermore, a spring-loaded locking element 51 is provided on the cover 5, which enables locking of the battery cell assembly to the electrical consumer.

[0024] As shown in detail Fig. 2, the heat sink element 3 has a protruding flange 30. The protruding flange 30 is arranged perpendicular to a surface of the heat sink element 3. As can be seen from Fig. 2, a protruding flange 30 is provided on a first side of the battery cell arrangement, to which the first side part 6 is fixed, and on a second side of the battery cell arrangement, in which the second side part 7 is fixed.

[0025] The protruding flange 30 has a plurality of first openings 31 (third form-locking elements). In this exemplary embodiment, a total of four first openings 31 are provided in the protruding flange 30. The openings each have a rectangular cross-section, with the rectangular cross-section of the first openings 31 being configured differently. Overall, however, the two protruding flanges 30 are of the same design.

[0026] How next Fig. As can be seen in Figure 4, the cover 5 has a protruding edge 52 in which a plurality of second openings 51 (second form-fitting elements) are formed. A cross section of the second openings 51 is identical to a cross section of the first openings 31 in the heat sink element 3. The protruding edge 52 of the cover 5 also protrudes perpendicularly from a base surface of the cover.

[0027] The first side part 6, as shown in Fig. 3, a protruding element 60 (first form-fitting element) is provided on a lid inner side 62. The protruding element 60 comprises a plurality of ribs 61. The ribs 61 protrude perpendicularly from a lid inner side 62 toward the interior of the battery cell arrangement 1. As shown in detail in Fig. 3, a cross section of the ribs 61 is complementary to the cross sections of the first and second openings.

[0028] In the assembled state of the battery cell arrangement 1, which is in the Fig. 5, Fig. 6 and Fig. 7, the projecting element 60 on the first side part 6 can thus first be passed through the second opening 51 of the cover 5 and then through the first opening 31 on the heat sink element 3 (compare Fig. 6).

[0029] On the protruding edge 51 of the cover 5, an undercut 53 is also formed, which projects in the direction of the first side part 6 (compare Fig. 4 and Fig. 6).

[0030] If a tensile load, for example due to dropping the battery cell arrangement 1, acts on it, the connection according to the invention between the cover 5, the first side part 6 and the heat sink element 3, starting from the Fig. 6 shown rest position, the tensile load on the connection as in Fig. 7 indicated by the arrow A. This allows the ribs 61 to move as shown in Fig. 7, indicated in dashed lines. However, as described above, the ribs 61 are essentially positively fixed in both the first opening and the second opening. This results in considerable resistance to the tensile load A, which is then distributed both between the cover 5 and the heat sink element 3. This prevents the ribs 61 from breaking and the housing 4 of the battery cell arrangement 1 from bursting open. In addition, due to the undercut 35 provided on the protruding edge 52, there is further force distribution in the connection between the first side part 6 and the cover 5 as well as the heat sink element 3. The undercut 53 also enables easy insertion of the ribs 61 both into the second opening 51 and then into the first opening 31.

[0031] In addition to the above-described connection between the heat sink element 3, the housing parts, and the cover 5, a screw connection 10 is also provided for the battery cell arrangement 1. The screw connection 10 connects the heat sink element 3 to the first side part 6 and the cover 5, or the heat sink element 3 to the second side part 7 and the cover 5.

[0032] The screw connection 10 is shown in detail in the Fig. 1 and Fig. 5 and comprises a plurality of screws 11. A first screw opening 12 is provided in the first side part 6. A second screw opening 13 is provided in the cover 5, and a third screw opening 14 is provided in the heat sink element 3. The screws 11 are guided through the first, second, and third screw openings 12, 13, and 14. This provides additional security for the connection between the components. It should be noted that the second side part 7 is fixed in the same way by a plurality of screw connections 10.

[0033] The second side part 7 of the housing 4 is fixed to the battery cell arrangement 1 in the same way as the first housing part 6, so that a detailed description of this fixing can be omitted.

[0034] The inventive connection between the heat sink element 3, the cover 5, and the housing parts 6, 7 thus enables a significant increase in the robustness of the battery cell arrangement. In particular, a secure connection can be achieved by nesting the fixing elements. The connection is adhesive-free, so that costs can be achieved, in particular, by eliminating the need for an adhesive and reducing assembly steps. Furthermore, a plurality of screw connections is additionally provided for additional, redundant fixing of the components. Overall, this results in a significant improvement in the quality of the battery cell arrangement 1, which can withstand falls from great heights without damage.

[0035] Assembly of the battery cell assembly 1 is preferably such that the battery cells are first provided with the heat sink element 3 surrounding the battery cells at the periphery of the battery cells. Then, the cover 5 is placed on the heat sink element 3, and the two side parts 6, 7 with the ribs 61 are passed through the first and second openings. Subsequently, the components are screwed together.

[0036] Fig. Figure 8 shows a battery cell arrangement with a component connection according to a second embodiment of the invention. The second embodiment essentially corresponds to the first embodiment, wherein, in addition to the first embodiment, as shown in Figure 1, a locking connection 8 is arranged on a free end of the ribs 61. The locking connection 8 comprises a locking lug 80 with an undercut 81. The undercut 81 engages, as shown in Fig. 8, a mounted state behind the protruding flange 30 on the heat sink element 3. This allows additional securing of the component connection of the battery cell arrangement. Preferably, the locking connection 8 is provided on each rib 61. As in the previous embodiment, the design on the second side part 7, which is shown in Fig. 8 is not shown, is designed identically.

Claims

[1] Battery cell assembly comprising: - at least one battery cell (2), - a cell holder element (3) at least partially enclosing the battery cell (2), - a multi-part housing (4) designed to accommodate the battery cell (2), wherein the housing (4) comprises at least a first housing part (6), in particular a side part, and a second housing part, in particular an interface housing part or a cover, - wherein the first housing part (6) has a first positive locking element (60), the second housing part (5) has a second positive locking element (51) and the cell holder element (3) has a third positive locking element (31), which are designed for positive connection to one another, - wherein at least one of the form-locking elements, in particular the second form-locking element, is designed as a protruding form-locking element, wherein the protruding form-locking element engages into the two other form-locking elements. [2] Battery cell arrangement according to claim 1, wherein at least one of the form-fitting elements has a reinforcing element, in particular a reinforcing insert. [3] Battery cell arrangement according to one of the preceding claims, - wherein the cell holder element (3) has, as a third form-fitting element, a protruding flange (30) with a first opening and the second housing part (5) has a second opening, and - wherein the first housing part (6) has a protruding element (60) complementary to the first opening and the second opening as a first form-fitting element, which is received in the first opening and the second opening. [4] Battery cell arrangement according to claim 3, wherein the first opening (31) on the projecting flange (30) of the cell holder element is a through-opening, in particular a polygonal one, and / or wherein the second opening (51) on the second housing part (5) is a through-opening, in particular a polygonal one. [5] Battery cell assembly according to claim 2, wherein a cross section of the first opening (31) is equal to a cross section of the second opening (51). [6] Battery cell arrangement according to one of the preceding claims, wherein at least one guide rail is arranged on the second housing part (5), which is adapted for connection to an electrical device. [7] Battery cell arrangement according to one of the preceding claims, wherein the protruding form-fitting element comprises a rib (61). [8] Battery cell arrangement according to one of the preceding claims, wherein the second housing part (5) has a projecting edge (52) in which the second opening (51) is formed. [9] Battery cell arrangement according to claim 8, wherein the projecting edge (52) has an undercut (53) which is arranged between the cell holder element (3) and the first projecting form-fitting element (61) of the first housing part (6). [10] Battery cell arrangement according to one of the preceding claims, further comprising a latching connection (8) which is formed at a free end of the first projecting form-fitting element (61) and the cover (5) and / or the cell holder element (3). [11] Battery cell arrangement according to one of the preceding claims, wherein a screw connection (10) is provided between the first housing part (6) and the second housing part (5). [12] Battery cell arrangement according to one of the preceding claims, further comprising a third housing part, in particular a second side part (7), which is designed corresponding to the first housing part (6). [13] Battery cell arrangement according to one of the preceding claims, wherein the first housing part (6), the cell holder element (3) and / or the second housing part or parts thereof, in particular a guide rail, are made of different materials, in particular different plastic materials. [14] Battery cell arrangement according to one of the preceding claims, wherein a distance of the second form-locking element (51) to a guide region (50) on the second housing part (5) is at most five times the height of the second form-locking element, in particular at most 30 mm.

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